Just Watched

Watch sinkhole devour Corvettes

A 40-foot-wide, 20-to-30-foot deep chasm tends to shake you up, say folks who've seen the hole with their own eyes. No one was hurt, but the mood in the museum is somber. They're a bit less shaken than they were Wednesday, when the sinkhole swallowed eight priceless Corvettes inside a part of the museum called the Sky Dome.

Just Watched

Corvettes swallowed up in sinkhole

"We've been given an OK and everything is safe," said museum spokeswoman Katie Frassinelli. About a dozen visitors were exploring the place Thursday morning, she said, but the Sky Dome remains closed indefinitely.

Nature's disturbance of this holy site started a wave of concern across the Corvette Nation that continued to ripple around the web Thursday.

"Who could fathom such a thing?" asked CNN commenter 440sixpack. "I don't live anywhere near this sort of geological risk, but still I'm tempted to arrange for a sub-surface analysis under my own garage just so I can still sleep good."

Photos: When the ground gives way 19 photos

Photos: When the ground gives way19 photos

When the ground gives way – An increasing number of sinkholes have appeared in and around the neighborhood where the Lotte World Tower is being built in Seoul, South Korea. The first one was discovered in June and several others have appeared since then, according to local media reports, causing the construction of what would be Seoul's tallest building to come under scrutiny.

Hide Caption

1 of 19

Photos: When the ground gives way19 photos

When the ground gives way – Eight Corvettes fell into a sinkhole that opened up beneath a section of the National Corvette Museum in Bowling Green, Kentucky, on February 12. The sinkhole was about 40 feet wide and 25-30 feet deep.

Hide Caption

2 of 19

Photos: When the ground gives way19 photos

When the ground gives way – The rear portion of a residential home is consumed by a sinkhole November 14 in Dunedin, Florida.

Hide Caption

3 of 19

Photos: When the ground gives way19 photos

When the ground gives way – A 60-foot-wide sinkhole formed underneath the Summer Bay Resort in Clermont, Florida, about 10 minutes from Walt Disney World, on August 11. One resort building collapsed, and another slowly sank.

Hide Caption

4 of 19

Photos: When the ground gives way19 photos

When the ground gives way – A backhoe is swallowed by a sinkhole in Montreal, Quebec, Canada, on August 6. The driver of the backhoe was not injured.

Hide Caption

5 of 19

Photos: When the ground gives way19 photos

When the ground gives way – A sinkhole killed a guard at a construction site in Shenzhen, China, on March 27. The sinkhole might have been caused by heavy rains and the collapsing of old water pipes running beneath the surface, the Shenzhen Special Zone Daily reported.

Hide Caption

6 of 19

Photos: When the ground gives way19 photos

When the ground gives way – Workers watch the demolition of the house where a sinkhole opened three days before in Seffner, Florida, on March 3. Sinkholes caused by acidic groundwater corroding the limestone or carbonate rock underground are common in Florida, according to the Florida Department of Environmental Protection.

Hide Caption

7 of 19

Photos: When the ground gives way19 photos

When the ground gives way – Buildings fell into a sinkhole near a subway construction site in Guangzhou, China, in January 2013. The hole measured about 1,000 square feet across and 30 feet deep and was without casualties, according to a state media report.

Hide Caption

8 of 19

Photos: When the ground gives way19 photos

When the ground gives way – A basketball court in Ortley Beach, New Jersey, fell into a sinkhole caused by Superstorm Sandy in November 2012.

Hide Caption

9 of 19

Photos: When the ground gives way19 photos

When the ground gives way – In July 2011, a man inspects a 40-foot-deep sinkhole that a family found after they heard a booming noise in their kitchen in Guatemala City, Guatemala.

Hide Caption

10 of 19

Photos: When the ground gives way19 photos

When the ground gives way – Construction on a subway line caused a huge sinkhole to form in a road in Beijing in April 2011.

Hide Caption

11 of 19

Photos: When the ground gives way19 photos

When the ground gives way – An aerial photo shows sinkholes created by the drying of the Dead Sea near Israel in 2011.

Hide Caption

12 of 19

Photos: When the ground gives way19 photos

When the ground gives way – A utility worker examines the area around a sinkhole caused by a broken water main in Chevy Chase, Maryland, in December 2010.

Hide Caption

13 of 19

Photos: When the ground gives way19 photos

When the ground gives way – Tropical Storm Agatha caused a sinkhole to open in Guatemala City in May 2010.

Hide Caption

14 of 19

Photos: When the ground gives way19 photos

When the ground gives way – A fire truck protrudes from a sinkhole as Los Angeles Mayor Antonio Villaraigosa talks to reporters in September 2009.

Hide Caption

15 of 19

Photos: When the ground gives way19 photos

When the ground gives way – A water main collapsed an entire block-long part of Ocean Park Boulevard in Santa Monica, California, in December 2002.

Hide Caption

16 of 19

Photos: When the ground gives way19 photos

When the ground gives way – In Orlando, a sinkhole 150 feet wide and 60 feet deep swallowed trees, pipelines and a section of sidewalk near an apartment building in June 2002.

Hide Caption

17 of 19

Photos: When the ground gives way19 photos

When the ground gives way – A 30-foot-deep sinkhole appeared in a busy street in a suburb east of downtown Los Angeles. A motorist drove into the hole but was rescued before a concrete slab fell onto the car.

Hide Caption

18 of 19

Photos: When the ground gives way19 photos

When the ground gives way – "The Great Blue Hole" is the name of a massive underwater sinkhole off the coast of Belize. The deeper you go, the clearer the water becomes, revealing amazing stalactites and limestone.

So, what the hell happened? How could a gaping hole just appear in such a wrong place?

Keep in mind that this is cave country. Western Kentucky is the home of Mammoth Cave National Park, the largest known cave system in the world. Sinkholes pop up constantly in these parts, usually caused by ground water eroding underground limestone over many years, forming a void underneath the surface of the earth. Eventually, the soil that was above the dissolving limestone has nothing to support it anymore, and it collapses.

"Right now, the ground at the museum seems like it's pretty stable," said Western Kentucky University geologist Jason Polk. Experts have assessed and inspected the entire building using ground monitoring equipment. Engineer Matthew Dettman, a 22-year professor at WKU, said sinkholes rarely form in clusters. "The likelihood that another is going to drop out is possible, but unlikely."

"The contractor in charge will certainly want to do some investigation to verify that we don't have any other issues in the building that we know of," Dettman said.

That contractor, Mike Murphy of Scott, Murphy and Daniel Construction, acknowledged that his business runs across at least one of these sinkhole situations every month.

"The only difference is this one swallowed eight collector Corvettes," he said. "But it is repairable."

He assured reporters Thursday the building was "in good condition, and the foundation and structure is in good condition."

But the cars. Those sweet cars. Oh, the humanity!

Some of them, Dettman said, are buried so deep in the hole that they can't be seen from the surface. "It's fascinating, and sad," he said Thursday morning on the phone. But "the timing could have been a lot worse," Dettman said. Amazing closed circuit security video shows the hole opening up early Wednesday morning before the museum was scheduled to open. "There are times where there are so many people in that room, you can't even move around."

Some of the museum workers were busy washing the cars that survived the sinkhole. "I can't say we've ever had to clear concrete dust off of our cars before," Frassinelli said. "They have to be really careful."

Polk, who spent most of Wednesday at the sinkhole site, said "the whole experience was surreal," adding that "it was definitely lucky for the people -- not so much for the Corvettes."

By the way, for the record, he says he's a 'Vette fan -- but he drives a Toyota.

For right now, Dettman says the risk is extremely minimal. The Sky Dome has been closed to the public, while visitors will be able to tour the rest of the facility. Another stroke of luck: the dome's round shape makes it less likely to collapse on itself, Dettman said. But about 10% of the concrete footing supporting the structure's signature red spire, which shoots high over the museum, has been "undermined" somewhat. "We do have to shore it up even though part of it is bearing on bedrock," he explained.

The Sky Dome has a long road to recovery. It will take at least four to six days to pull the Corvettes out of the chasm, and then construction crews will begin filling in the hole, Murphy said.

Timing may have been good for the Sky Dome, but it was bad on another level. The sinkhole comes as the museum prepares to celebrate its 20th anniversary this August. Big doings are in the works, including the grand opening of a new nearby MotorSports Park, where sinkholes were found and dealt with during construction.

"Sinkholes are so common here that I would have been shocked if they hadn't found any," Dettman said.

But museum executive director Wendell Strode said the Sky Dome will reopen in time for the festivities. "August is our target date," he said.

How do you fix a sinkhole? You can fill it in with dirt or other types of material. Or sometimes, it's impossible to fix, and the location has to be abandoned. It depends on the situation, said Polk.

Discussions about how to proceed with the museum sinkhole are expected to continue Thursday, and there's no firm plan yet. No one really knows how long it will be before we know if the Sky Dome will survive this attack by Mother Nature.